Purpose: The purpose of this study was to evaluate how risk estimates generated from cumulative meta-analysis performs over time for drugs having their benefit/risk ratio re-evaluated due to safety issues and, additionally, assess whether results are consistent with regulatory authorities' conclusions.
Methods: Four major regulatory authorities were searched for their issued safety alerts supported by longitudinal, comparative studies (experimentals and/or observationals). The random-effects model was used to pooled odds ratios (OR) over time by including studies according to the year they first became available.
Results: Seventeen safety alerts were included in this study. In 2008, proton-pump inhibitors (PPIs) were associated with an increased risk for bone fractures [OR 1.25, 95 % confidence interval (CI) 1.00-1.55, P = 0.049); the US Food and Drug Association (FDA) issued a safety alert in 2010 and added warnings to the label. An increased risk for Clostridium-difficile-associated diarrhea was pooled for PPIs in 2004 (OR 1.89, 1.19-3.02, P = 0.007); US FDA issued a safety alert in 2012, adding warnings to the label. PPIs were associated with pneumonia in 2009 (OR 1.40, 1.06-1.85, P = 0.017); US FDA issued an alert in 2012 but concluded that the benefit/risk (B/R) ratio remains positive. Statins were associated with an increased risk for diabetes (OR 1.07, 1.01-1.15, P = 0.033) in 2008. The European Medicines Agency (EMA) issued an alert in 2012, including warnings to the label. The remaining cumulative meta-analyses did not estimate increased risks in advance of regulatory decisions.
Conclusion: This study demonstrates that meta-analysis may help predict iatrogenic risks. However, between-study heterogeneity can considerably affect the estimated results, and therefore, this technique should not replace further assessments during BR ratio re-evaluations.